Photographic emulsion layer containing a 3-pyrazolidone



June 19, 1956 HOOD EI'AL 2,751,297

PHOTOGRAPHIC EMULSION LAYER CONTAINING A 3-PYRAZOLIDONE Filed Aug. 3. 1953 S/L V E HAL/0E EMUL S/OIV CONTA/lV/IVG A 3 PYRAZOL /0 ONE l0 SUPPOR 7' 6L4 Y M. HOOD PAUL R. CROOKSHA/VK INVENTORS BY M X M ATTORNEY 8 AGENT United States Patent PHOTOGRAPHIC EMULSION LAYER CON- TAINING A 3-PYR-AZOLIDONE Glay M. Hood and Paul R. Crookshank, Rochester, N. Y

assignors to Eastman Kodak Company, N. Y., a corporation of New Jersey Application August 3, 1953, Serial No. 371,948 12 Claims. (Cl. 95-7) '9 Rochester,

it is desirable to obtain rapid and reasonably complete development of the exposed emulsion layer. Wehave discovered that if certain 3-pyrazolidone compounds are incorporated into silver halide emulsion layers, particularly those emulsion layers which-are normally slow developing or in those cases where a short complete development is desired, development proceeds much faster than when the 3-pyrazolidone compounds are not present in the emulsion layer.

The accompanying drawings show in; greatly enlarged cross-sectional view the appearance of a representative photographic element contemplated by our invention. In the element of the drawings layer represents a support such as paper, cellulose ester, etc., and layer lit the emulsion layer of the invention containing a mixture of silver halide and a 3-pyrazolidone compound.

The 3-pyrazolidone compounds employed inthe emulsions have thegeneral structure in which the various R groups repre sent substituents such as hydrogen, alkyl heterocyclicor aryl* groups, for-example, R can be benzothiazolyl or an -aryl;fgroup--of the benzene or naphthalene series, substituted or not;however, R cannot be a hydrogen atom inasmuch as 3-pyrazolidone compounds containing no substituent other than hydrogen in the l-position of the nucleus, such as 3.-pyraz- 1. l-phenyl-3-pyrazolidone l-p-tolyl-3-pyrazolidone 5-phenyl-3-pyrazolidone 5-methyl-3-pyrazolidone 1-p-chlorophenyl-3-pyrazolidone 1-phenyl-S-phenyl-3pyrazolidone l-m-tolyl-3-pyrazolidone 1 phenyl-S-methyl-3-pyrazolidone 1-p-tolyl-5 phenyl-3pyrazolidone l-m-tolyl-S-pyrazolidone 2,751,297 Patented June 19, 1956 l-p-methoxyphenyl 3 pyrazolidone l-acetamidophenyl-3-pyrazolidone 1-phenyl-2-acetyl-4,4:dimethyl-3-pyrazolidone l-phenyl-4,4-dimethyl-3-pyrazolidone l-m-aminophenyl 4=methyl-4-propyl-3-pyrazolidone 'l-o-chlorophenyl-4-methyl-4-ethyl-3-pyrazolidone 'l-m-acetamidophenyl-4,4-diethyl-3-pyrazolidone l (p-fi-hydroxyethylphenyl) 4,4-dimethyl 3-pyrazolidone 1-p-hydroxyphenyl-4,4-dimethyl-3-pyrazolidone l -p-methoxyphenyl 4;4-diethyl-3pyrazolidone l-p=tolyl 4,4-dimethyl*3-pyrazolidone l (7-hydroxy-2-naphthyl) 4-methyl 4 n-p-ropyl -3- pyrazolidone l-p-diphenyl-4,4 dimethyl-3-pyrazolidone 1-(p-B-hydroxye'thylphenyl)-3-pyrazolidone l-o-tolyl3-pyrazolidone 1=o-tolyl-4,4-dimethyl-3 pyrazolidone 1-benzothiazolyl 3 pyrazolidone Compounds l to '12 can be prepared by the methods described in British Patents 679,677 and 679,678. Compounds 13 to 23 and26above are representative of 4,4- dialkyl-3-pyrazolidone compounds useful in the'invention and these compounds are described and claimed in the Allen et al. U. 'S.,patent application Serial No. 372,148, filed August 3,1953.

The w-hydroxyalkylphenyl-3-pyrazo1idones in which the "alkylgroup preferably contains from 1 to 4 carbon atoms, for example, compoundslS and 24 above, are described in the Allen et al. invention and in the Reynolds and "Tin'ker U; su patenttapplication Serial No. 372,167, filed concurrently.

The '3-pyrazolidone compounds can be used in silver halide-emulsionsifor the purposes of the invention with gratifyingresults in a rather wide range of concentration. Usefullresults can be obtained, for example, with from about 0.2 to 2.0 grams of the B-pyrazolidone compound per mol of silver nitrate used in making the emulsion and converted to silverhalide. However,'both smaller and largeriquantities of'the'compounds than indicated can be. used with good results. The particular silver halide infthe emulsioniis not especially critical nor is the particular'method used for preparing the emulsion. Thus oneior more of the.3.-pyrazolidone compounds cantbe added toemulsions containing mixtures of silver bromide, silver chloride and silver iodide such as present in emulsion' of well known types. However; the 3-pyrazolidones are-particularly useful in conjunction with bromoiodide emulsions which normally develop slowly andinemulsions which normally require a short first development as in bleach redevelopment reversal processes. The 3-pyrazolidone compounds are added in water solution to the emulsions at any stage in their preparation but are conveniently added after the final digestion'and just before coating. .As will be apparent, the emulsions may contain the usual addenda including .antifoggants, spreading agents, coupler compounds, etc. Such emulsions zare adaptable to use in forming single as well as multi-layer films useful in color photography which customarily include two or more emulsion layers on -a support :sensitized to diiferent regions of the'visiblespectrum and which may or may not contain coupler compounds. According to our invention, such color films carry at-least .one emulsion layer containing one or more of the-pyrazoemulsion or to stabilize it can be incorporated in :a hydrophilic colloid layer such asgelatin adjacent -to.=the

emulsion layer with the result. that materialdevelopment acceleration and improvement in emulsion :stabilityere obtained thereby.

EXAMPLE 1 Samples of a finished washed bromo-iodide emulsion were provided. To the respective samples of melted emulsion were added aqueous solutions of the 3-pyrazolidone compounds indicated in the fololwing table. The samples were coated successively on a paper stock and dried. The samples were then given continuous wedge exposures and developed for 20 to 45 seconds both when the samples were fresh and after 3-day incubation at 120 F. and 60 percent relative humidity, development being carried out in a conventional Elon-hydroquinone developer. Sensitometric evaluation of the developed samples produced the data tabulated in the following table. The bar gamma values in the table are a measure of the contrast of the developed samples and a description of the determination of this value is given in the American Standards Association Bulletin entitled Sensitometry and Grading of Photographic Papers, January 8, 1953. In considering the data of the table, the development acceleration effect of using the B-pyrazolidone compounds in the emulsions should be made between samples detioned previously, it appears essential that the 3-pyrazolidone compounds contain a substituent other than hydrogen in the l-position of the nucleus since compounds such as 3-pyrazolidone do not produce the desired effect 5 when incorporated into silver halide emulsion layers.

What we claim is:

1. A light-sensitive photographic emulsion comprising a mixture of unexposed silver halide and a-3-pyrazolidone having the following general structure veloped for 20 seconds and the stabilizing eifect of the E2 compounds should be evaluated on the basis of the samples developed for 45 seconds. It will be apparent from 1 H the data that the 3-pyrazolidone compounds materially increase the contrast of the emulsion and stabilize the T emulsion against contrast loss on aging. R

Use of pyrazolidones in a washed bromoiodide emulsion Bar Gamma D-rnax.

tar I B on, Chemical mglmole 20 Sec. Dev. Bee. Dev. 20 Sec. Dev. 45 See. Dev.

Silver Halide Fresh 3Day Fresh 3108. Fresh 3Day Fresh 3Day Inc. Inc. 1110. Inc.

Check None 1.00 s1 1. 7a 1. 1. 01 s9 1. 2a 1. 25 it? is: 1a 1a 112 5 .28 0 437 1. 41 95 1. ss 1. 70 1. 1s 1. 12 1. 27 1. as 219 1. 21 .93 1. s9 1. as 1.15 1. 04 1. 27 1. 2e at 1a 1a 1a 4'"dimeihYLl'phenyl'ii'pyrawndune 431 1: 25 I as 1185 11 e5 11 1g 11 11 2; i1 2% 219 1. 20 .93 1. s3 1. 65 1. 15 1.00 1. 27 1. 2s tit l-tt tit it; 1a 12 1e htdimethym@myn'a'pymtlmm wis? 11 29 I as 1161 1'. s2 1: 15 1102 11 is iI 219 76 9s 1. 71 1. 64 9s 1. 02 1. 25 1. 24 1, 75% 1.32 1.22 39 13 1 2 21 1.27 1'(Mflydmyeihybphwyl)'a'pmmndme--'- 237 1: 21; I91 11 11 1: 62 110 110 1122 i1 3% 219 1. 59 .so 1. e9 1. 1. 04 1.10 1. 25 1. 24

EXAMPLE 2 To a sample of a normally slow-developing brornoiodide emulsion used in reversal processes was added 8.77 milligrams of 1-phenyl-3-pyrazolidone per mol of silver nitrate used in making the emulsion and converted to silver halide. The emulsion was coated as usual on a paper base, exposed, developed in a caustic hydroqui none developer and evaluated sensitometrically. The data obtained showed that the gamma for samples of the emulsion containing no pyrazolidone compound which were developed 15, 30 and 45 seconds respectively, were 0.75, 0.98 and 1.05, whereas the samples containing the pyrazolidone compound developed under the same conditions had gammas of 1.08, 1.27 and 1.35. This example illustrates the effect which may be expected in reversal processes where it is desired to obtain a rapid complete development of the negative image where the first or negative development is usually short.

The other 3-pyrazolidone compounds such as those specifically mentioned above are useful in our invention as accelerators and stabitizers for emulsions. As men- 55 wherein R represents a mononuclear aryl group of the benzene series and R1 and R2 each represent an alkyl group of from 1 to 4 carbon atoms, in a small amount not in excess of about 2 grams per mol of silver halide in the emulsion.

3. A light-sensitive photographic emulsion layer comprising a mixture of unexposed silver halide and l-phenyl- 4,4-dimethyl-3-pyrazolidone, in a small amount not in excess of about 2 grams per mol of silver halide in the emulsion.

4. A light-sensitive photographic emulsion layer comprising a mixture of unexposed silver halide and a l-tolyl- 4,4-dialkyl-3-pyrazolidone, in a small amount not in excess of about 2 grams per mol of silver halide in the emulsion.

5. A light-sensitive photographic emulsion layer comprising a mixture of unexposed silver halide and .l-ptolyl-4,4-dimethyl-3-pyrazolidone, in a small amount not in excess of about 2 grams per mol of silver halide in, the

emulsion.

6. A light-sensitive photographic emulsion compriswherein R represents a mononuclear aryl group of the benzene series, in a small amount not in excess of about 2 grams per mol of silver halide in the emulsion.

7. A light-sensitive photographic emulsion layer comprising a mixture of unexposed silver halide and 1-phenyl- 3-pyrazolidone, in a small amount not in excess of about 2 grams per mol of silver halide in the emulsion.

8. A light-sensitive photographic emulsion layer comprising a mixture of unexposed silver halide and a 1- tolyl-3-pyrazolidone, in a small amount not in excess of about 2 grams per mol of silver halide in the emulsion.

9. A light-sensitive photographic emulsion layer comprising a mixture of unexposed silver halide and l-ptolyl-S-pyrazolidine, in a small amount not in excess of about 2 grams per mol of silver halide in the emulsion.

10. A light-sensitive photographic emulsion layer comprising a mixture of unexposed silver halide and a l-whydroxyalkylphenyl-3-pyrazolidone, in a small amount not in excess of about 2 grams per mol of silver halide in the emulsion.

11. A light-sensitive photographic emulsion layer comprising a mixture of unexposed silver halide and 1(p-,8- hydroxy-ethylphenyl)-3-pyrazolidone, in a small amount not in excess of about 2 grams per mol of silver halide in the emulsion.

12. A light-sensitive photographic element comprising a support, an unexposed silver halide emulsion layer, and a hydrophilic colloid layer adjacent to said emulsion layer containing a 3-pyrazolidone having the following general structure wherein R represents a member of the group consisting of heterocyclic groups and aryl groups of the benzene and naphthalene series and R1, R2, R3 and R4 each represent a member of the group consisting of a hydrogen atom, a mononuclear aryl group of the benzene series, and an alkyl group containing from 1 to 4 carbon atoms, in a small amount not in excess of about 2 grams per mol of silver halide in the emulsion.

References Cited in the file of this patent UNITED STATES PATENTS 742,405 Eichengrun et al. Oct. 27, 1903 2,477,462 McQueen July 26, 1949 2,672,416 Stanton Mar. 16, 1954 FOREIGN PATENTS 679,677 Great Britain Sept. 24, 1952 679,678 Great Britain Sept. 24, 1952 

1. A LIGHT-SENSITIVE PHOTOGRAPHIC EMULSION COMPRISING A MIXTURE OF UNEXPOSED SILVER HALIDE AND A 3-PYRAZOLIDONE HAVING THE FOLLOWING GENERAL STRUCTURE 